OZ951

I have been experiencing an odd noise from the front end of my car, generally under heavy braking but the first time I heard it was under normal light braking as I pulled up to some lights on the way home from a track day.

It can be heard in the attached video most clearly at time 54sec-58sec as I brake hard at the end of the long straight. It is there in other braking zones but not as audible due to the lighter braking.

In person the sound sounds like a ball bearing running down a corrugated plastic pipe.

The noise is evident on track and occasionally on the way home from the track but otherwise it goes away between track days. Having said that The car isn't getting much use other than driving to and from the track, so lets just say it isnt really evident when driving to the track.

I have replaced pads and discs (RS-29s) and I feel no play in the wheel bearings.

I've been trying to figure out this noise for months and none of the 250 noise threads I found on RL seemed to be related.

Any thoughts appreciated.

Barn996

Very distinct noise, but I really have no idea. Great video by the way, nice lines.

himself

You should post this in the racing sub-forum. There are gurus galore - including many folks that build race cars.

I really couldn't hear anything other than the high pitched squeal. iPad speaker isn't hi-fi...

-td

Dervish

Random suggestion but are you running cup ducts or similar? 1 side of mine was slightly loose and rubbed in the inner wheel surface causing an audible scrape on heavy ish braking. This is easily checked though as you can clearly see the worn duct edge.

Yours definitely sounds more metallic though.
?

OZ951

Cross posted as suggested, thanks.

I'm running the GT3 ducts, no clearance issues noted there.

I'm wondering if it's possible for the ABS pump to make such a noise.

OZ951

Thought I better update this post in case anyone finds themselves with a similar noise in the future. The noise that can be heard in the video has been eliminated by replacing the front right ABS sensor.

Pac996

I was thinking maybe ABS like you found out it was. I couldn't spot any real hard braking by visual or audio so I was kind of lost hearing the noise. You need to hit the brakes so hard your face is by the windshield I know my abs gets grabby and creates some wheel hop when trying to stop fast on the very last part of the stop.

Sensors can use some cleaning at times when they are building up road junk on them and the wheel section they monitor.